Hydride vapour phase epitaxy growth, crystal properties and dopant incorporation in gallium nitride

Hydride vapour phase epitaxy growth, crystal properties and dopant incorporation in gallium nitride PDF Author: Patrick Hofmann
Publisher: BoD – Books on Demand
ISBN: 3752884924
Category : Science
Languages : en
Pages : 166

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Book Description
This dissertation employs doping to investigate basic gallium nitride (GaN) crystal properties and to solve challenges of the hydride vapour phase epitaxy (HVPE) growth process. Whereas the first chapter is a short introduction to the history of the GaN single crystal growth, the 2nd chapter introduces to current crystal growth techniques, discusses properties of the GaN material system and the resulting influence on the applicable crystal growth techniques. HVPE, as a vapour phase epitaxy crystal growth method will be explained in greater detail, with focus on the used vertical reactor and its capabilities for doping. The 3rd chapter then focusses on point defects in GaN, specifically on intentionally introduced extrinsic point defects used for doping purposes, i.e. to achieve p-type, n-type or semi-insulating behaviour. Different dopants will be reviewed before the diffusion of point defects in a solid will be discussed. The in-situ introduction of iron, manganese, and carbon during crystal growth is employed in chapter 4 to compensate the unintentional doping (UID) of the GaN crystals, and therefore to achieve truly semi-insulating behaviour of the HVPE GaN. However the focus of this chapter lies on the characterisation of the pyroelectric coefficient (p), as semi-insulating properties are a necessary requirement for the applied Sharp-Garn measurement method. The creation of tensile stress due to in-situ silicon doping during GaN crystal growth is the topic of the 5th chapter. The tensile stress generation effect will be reproduced and the strain inside the crystal will be monitored ex-situ employing Raman spectroscopy. The n-type doping is achieved by using a vapour phase doping line and a process is developed to hinder the tensile strain generation effect. The 6th chapter concentrates on the delivery of the doping precursor via a solid state doping line, a newly developed doping method. Similar to chapter 5, the doping line is characterised carefully before the germanium doping is employed to the GaN growth. The focus lies on the homogeneity of the germanium doping and it is compared compared to the silicon doping and the vapour phase doping line. Benefits and drawbacks are discussed in conjunction with the obtained results. The germanium doping via solid state doping line is applied to the HVPE GaN growth process to measure accurately growth process related properties unique to the applied set of GaN growth parameters.

Hydride vapour phase epitaxy growth, crystal properties and dopant incorporation in gallium nitride

Hydride vapour phase epitaxy growth, crystal properties and dopant incorporation in gallium nitride PDF Author: Patrick Hofmann
Publisher: BoD – Books on Demand
ISBN: 3752884924
Category : Science
Languages : en
Pages : 166

Get Book Here

Book Description
This dissertation employs doping to investigate basic gallium nitride (GaN) crystal properties and to solve challenges of the hydride vapour phase epitaxy (HVPE) growth process. Whereas the first chapter is a short introduction to the history of the GaN single crystal growth, the 2nd chapter introduces to current crystal growth techniques, discusses properties of the GaN material system and the resulting influence on the applicable crystal growth techniques. HVPE, as a vapour phase epitaxy crystal growth method will be explained in greater detail, with focus on the used vertical reactor and its capabilities for doping. The 3rd chapter then focusses on point defects in GaN, specifically on intentionally introduced extrinsic point defects used for doping purposes, i.e. to achieve p-type, n-type or semi-insulating behaviour. Different dopants will be reviewed before the diffusion of point defects in a solid will be discussed. The in-situ introduction of iron, manganese, and carbon during crystal growth is employed in chapter 4 to compensate the unintentional doping (UID) of the GaN crystals, and therefore to achieve truly semi-insulating behaviour of the HVPE GaN. However the focus of this chapter lies on the characterisation of the pyroelectric coefficient (p), as semi-insulating properties are a necessary requirement for the applied Sharp-Garn measurement method. The creation of tensile stress due to in-situ silicon doping during GaN crystal growth is the topic of the 5th chapter. The tensile stress generation effect will be reproduced and the strain inside the crystal will be monitored ex-situ employing Raman spectroscopy. The n-type doping is achieved by using a vapour phase doping line and a process is developed to hinder the tensile strain generation effect. The 6th chapter concentrates on the delivery of the doping precursor via a solid state doping line, a newly developed doping method. Similar to chapter 5, the doping line is characterised carefully before the germanium doping is employed to the GaN growth. The focus lies on the homogeneity of the germanium doping and it is compared compared to the silicon doping and the vapour phase doping line. Benefits and drawbacks are discussed in conjunction with the obtained results. The germanium doping via solid state doping line is applied to the HVPE GaN growth process to measure accurately growth process related properties unique to the applied set of GaN growth parameters.

Vertical Gallium Nitride PowerDevices: Fabrication and Characterisation

Vertical Gallium Nitride PowerDevices: Fabrication and Characterisation PDF Author: Rico Hentschel
Publisher: BoD – Books on Demand
ISBN: 3752641762
Category : Science
Languages : en
Pages : 156

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Book Description
Efficient power conversion is essential to face the continuously increasing energy consumption of our society. GaN based vertical power field effect transistors provide excellent performance figures for power-conversion switches, due to their capability of handling high voltages and current densities with very low area consumption. This work focuses on a vertical trench gate metal oxide semiconductor field effect transistor (MOSFET) with conceptional advantages in a device fabrication preceded GaN epitaxy and enhancement mode characteristics. The functional layer stack comprises from the bottom an n+/n--drift/p-body/n+-source GaN layer sequence. Special attention is paid to the Mg doping of the p-GaN body layer, which is a complex topic by itself. Hydrogen passivation of magnesium plays an essential role, since only the active (hydrogen-free) Mg concentration determines the threshold voltage of the MOSFET and the blocking capability of the body diode. Fabrication specific challenges of the concept are related to the complex integration, formation of ohmic contacts to the functional layers, the specific implementation and processing scheme of the gate trench module and the lateral edge termination. The maximum electric field, which was achieved in the pn- junction of the body diode of the MOSFET is estimated to be around 2.1 MV/cm. From double-sweep transfer measurements with relatively small hysteresis, steep subthreshold slope and a threshold voltage of 3 - 4 V a reasonably good Al2O3/GaN interface quality is indicated. In the conductive state a channel mobility of around 80 - 100 cm2/Vs is estimated. This value is comparable to device with additional overgrowth of the channel. Further enhancement of the OFF-state and ON-state characteristics is expected for optimization of the device termination and the high-k/GaN interface of the vertical trench gate, respectively. From the obtained results and dependencies key figures of an area efficient and competitive device design with thick drift layer is extrapolated. Finally, an outlook is given and advancement possibilities as well as technological limits are discussed.

Chemical Vapor Deposition: 1960-1980

Chemical Vapor Deposition: 1960-1980 PDF Author: Donald T. Hawkins
Publisher: Springer
ISBN:
Category : Reference
Languages : en
Pages : 762

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Nitrides and Related Wide Band Gap Materials

Nitrides and Related Wide Band Gap Materials PDF Author: A. Hangleiter
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 440

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Book Description
The Symposium on 'Nitrides and related wide band gap materials' at the 1998 Spring Meeting of the European Materials Research Society (E-MRS) in Strasbourg, France, was the third Symposium of its kind at an E-MRS meeting. Beginning in 1996, these Symposia enjoyed a steadily increasing popularity among European and international nitride researchers. Contributions covered the areas of hetero-epitaxy, bulk growth, structural, electrical and optical characterisation and device fabrication. Researchers from about 20 different countries presented their work at this symposium. Naturally, most papers were from within Europe (Germany, France, Russia and the United Kingdom) but there was also a remarkable number of contributions from overseas (USA, Japan and Korea.) For about 5 years now, semiconducting group-III nitrides have attracted an enormous level of research activity all over the world. Essentially this was triggered by the breakthroughs achieved by Shuji Nakamura and his group in Japan, who succeeded in making highly efficient blue, green and yellow light emitting diodes as well as violet laser diodes based on A1GaInN. Since then, intensive research related to material growth, device development, as well as to the fundamental properties of these materials is being carried out. The outstanding contribution of Shuji Nakamura to this field was underlined by his plenary lecture during this E-MRS meeting. He presented his most recent progress towards amber LED's and long-lived violet laser diodes.

Electroluminescence I

Electroluminescence I PDF Author:
Publisher: Academic Press
ISBN: 0080864627
Category : Science
Languages : en
Pages : 353

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Book Description
The volume "Electroluminescence" for the first time covers (almost) all kinds of electroluminescence. In its broadest sense electroluminescence is the conversion of electric power into optical power - light. The way, in which this goal is accomplished, and the goal, the application itself, has varied over time. First reported in the scientific literature in 1936 by the French physicist G. Destriau, it was for quite some decades the glow of a powder embedded in a resin under the action of an alternating voltage. The dream of "cold light" for illumination was born in the 50s. Modern semiconductor technology, using p-n juntion, but not in silicon or germanium, but in GaAs and GaP, created in the 70s the tiny Light emitting Diodes. Today about 50 for every human being have been sold. They are everywhere for signaling and display of numbers and short texts. And they are at the verge of an era of solid state lighting, replacing gradually incandescent bulbs and fluorescent lamps. In the first half of 1999 several joint ventures between giants of the lighting industry and manufacturers of LEDs became known, including names as Philips, General Electric, Osram and Hewlett Packard, Emtron and Siemens, The reason, blue light emission of LEDs, for so long researched for unsuccessfully, has been achieved.Signaling, lighting will be the domains of LEDs in the next decades - a good start in the 21st millenium. But a the same time a paradigm shift in the display industry could come about. Dominated for the last 10 years by Liquid Crystal Displays (LCD), which are reflecting or transmitting light from extra light sources, self-emitting displays will challenge this dominance. Capable of handling very complex information by multiplexed addressing of millions of picture elements (pixels) in full color electroluminescence in the form of Organic LEDs and Thin Film Electroluminescence is gaining markets. Both technologies, much less matured than LED, incorporate much different physical features. The broad materials potential almost unexplored in both cases, they are good for surprises.The volume tries to present overviews ovber the 3 different technologies, covering in each case the mechanisms, the most important material properties, essential for the implementation of the working principles, the major applications and the system aspects. The reader will learn how the new long-life, maintenance free, power saving red traffic lights in the Silicon Valley function, and what the tail lights of his next car will be. The fascinating physics of polymer light emitters, eventually manufactured in a roll-to roll process, for cellular phones, or hand-held wireless computers, will become transparent. And why is it that up to now only sulfides can be used for the simplest design of displays capable of proven multiplex ratios of 1000? The comparison of the different electroluminescences, if this plural exists, will hopefully give experts of one of the fields, students of any of them, and application engineers new insights and ideas. Materials scientists and engineers will be caught by the comparison in analyzing what else one could provide to improve performance.

Ceramic Abstracts

Ceramic Abstracts PDF Author:
Publisher:
ISBN:
Category : Ceramics
Languages : en
Pages : 950

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Chemical Abstracts

Chemical Abstracts PDF Author:
Publisher:
ISBN:
Category : Chemistry
Languages : en
Pages : 2002

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Cumulative Subject and Author Index Including Tables of Contents, Volumes 1-50

Cumulative Subject and Author Index Including Tables of Contents, Volumes 1-50 PDF Author:
Publisher: Academic Press
ISBN: 0080864511
Category : Technology & Engineering
Languages : en
Pages : 445

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Book Description
Since its inception in 1966, the series of numbered volumes known as Semiconductors and Semimetals has distinguished itself through the careful selection of well-known authors, editors, and contributors. The "Willardson and Beer" Series, as it is widely known, has succeeded in publishing numerous landmark volumes and chapters. Not only did many of these volumes make an impact at the time of their publication, but they continue to be well-cited years after their original release. Recently, Professor Eicke R. Weber of the University of California at Berkeley joined as a co-editor of the series. Professor Weber, a well-known expert in the field of semiconductor materials, will further contribute to continuing the series' tradition of publishing timely, highly relevant, and long-impacting volumes. Some of the recent volumes, such as Hydrogen in Semiconductors, Imperfections in III/V Materials, Epitaxial Microstructures, High-Speed Heterostructure Devices, Oxygen in Silicon, and others promise indeed that this tradition will be maintained and even expanded.Reflecting the truly interdisciplinary nature of the field that the series covers, the volumes in Semiconductors and Semimetals have been and will continue to be of great interest to physicists, chemists, materials scientists, and device engineers in modern industry.

Crystal Growth Bibliography

Crystal Growth Bibliography PDF Author:
Publisher: Springer Nature
ISBN: 1461596181
Category :
Languages : en
Pages : 270

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Electrical & Electronics Abstracts

Electrical & Electronics Abstracts PDF Author:
Publisher:
ISBN:
Category : Electrical engineering
Languages : en
Pages : 2240

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